This is a note to let you know that I've just added the patch titled
Subject: USB: add usb_autopm_get_interface_burst()
to my gregkh-2.6 tree. Its filename is
usb-add-usb_autopm_get_interface_burst.patch
This tree can be found at
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
>From [email protected] Fri Jul 6 11:21:32 2007
From: Alan Stern <[email protected]>
Date: Fri, 6 Jul 2007 14:21:26 -0400 (EDT)
Subject: USB: add usb_autopm_get_interface_burst()
To: Greg KH <[email protected]>
Cc: USB development list <[email protected]>
Message-ID: <[email protected]>
This patch (as929) adds usb_autopm_get_interface_burst() to the
autosuspend programming interface. It is intended for situations
where I/O events occur in bursts of activity; it reduces overhead by
not cancelling the device's autosuspend timer.
Signed-off-by: Alan Stern <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/core/driver.c | 50 +++++++++++++++++++++++++++++++++++++---------
include/linux/usb.h | 1
2 files changed, 42 insertions(+), 9 deletions(-)
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1126,6 +1126,7 @@ static int usb_suspend_both(struct usb_d
/**
* usb_resume_both - resume a USB device and its interfaces
* @udev: the usb_device to resume
+ * @burst: flag for burst-mode operation (don't disable the suspend timer)
*
* This is the central routine for resuming USB devices. It calls the
* the resume method for @udev and then calls the resume methods for all
@@ -1136,6 +1137,13 @@ static int usb_suspend_both(struct usb_d
* tree and assuring that @udev will be able to resume. If the parent is
* unable to resume successfully, the routine fails.
*
+ * If @burst is set then @udev's autosuspend timer isn't cancelled. This
+ * helps avoid timer overhead in situations where bursts of I/O requests
+ * occur during a short period of time. If the timer expires later while
+ * @udev is still busy, nothing will happen and the timer won't be restarted.
+ * If the timer expires after @udev has become idle again, it will either
+ * reschedule itself or perform an autosuspend as usual.
+ *
* The resume method calls are subject to mutual exclusion under control
* of @udev's pm_mutex. Many of these calls are also under the protection
* of @udev's device lock (including all requests originating outside the
@@ -1151,14 +1159,15 @@ static int usb_suspend_both(struct usb_d
*
* This routine can run only in process context.
*/
-static int usb_resume_both(struct usb_device *udev)
+static int usb_resume_both(struct usb_device *udev, int burst)
{
int status = 0;
int i;
struct usb_interface *intf;
struct usb_device *parent = udev->parent;
- cancel_delayed_work(&udev->autosuspend);
+ if (!burst)
+ cancel_delayed_work(&udev->autosuspend);
if (udev->state == USB_STATE_NOTATTACHED) {
status = -ENODEV;
goto done;
@@ -1233,7 +1242,7 @@ static int usb_autopm_do_device(struct u
WARN_ON(udev->pm_usage_cnt < 0);
if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
if (udev->state == USB_STATE_SUSPENDED)
- status = usb_resume_both(udev);
+ status = usb_resume_both(udev, 0);
if (status != 0)
udev->pm_usage_cnt -= inc_usage_cnt;
else if (inc_usage_cnt)
@@ -1338,7 +1347,7 @@ int usb_autoresume_device(struct usb_dev
* its device's autosuspend state.
*/
static int usb_autopm_do_interface(struct usb_interface *intf,
- int inc_usage_cnt)
+ int inc_usage_cnt, int burst)
{
struct usb_device *udev = interface_to_usbdev(intf);
int status = 0;
@@ -1351,7 +1360,7 @@ static int usb_autopm_do_interface(struc
intf->pm_usage_cnt += inc_usage_cnt;
if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) {
if (udev->state == USB_STATE_SUSPENDED)
- status = usb_resume_both(udev);
+ status = usb_resume_both(udev, burst);
if (status != 0)
intf->pm_usage_cnt -= inc_usage_cnt;
else if (inc_usage_cnt)
@@ -1401,7 +1410,7 @@ void usb_autopm_put_interface(struct usb
{
int status;
- status = usb_autopm_do_interface(intf, -1);
+ status = usb_autopm_do_interface(intf, -1, 0);
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__FUNCTION__, status, intf->pm_usage_cnt);
}
@@ -1445,7 +1454,7 @@ int usb_autopm_get_interface(struct usb_
{
int status;
- status = usb_autopm_do_interface(intf, 1);
+ status = usb_autopm_do_interface(intf, 1, 0);
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__FUNCTION__, status, intf->pm_usage_cnt);
return status;
@@ -1453,6 +1462,29 @@ int usb_autopm_get_interface(struct usb_
EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
/**
+ * usb_autopm_get_interface_burst - increment a USB interface's PM-usage counter for burst-mode operation
+ * @intf: the usb_interface whose counter should be incremented
+ *
+ * This routine does almost exactly the same thing as
+ * usb_autopm_get_interface() above. The only difference is that it
+ * doesn't disable the device's autosuspend timer, so there's less
+ * overhead when the routine is called over and over again for a burst
+ * of I/O.
+ *
+ * This routine can run only in process context.
+ */
+int usb_autopm_get_interface_burst(struct usb_interface *intf)
+{
+ int status;
+
+ status = usb_autopm_do_interface(intf, 1, 1);
+ dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
+ __FUNCTION__, status, intf->pm_usage_cnt);
+ return status;
+}
+EXPORT_SYMBOL_GPL(usb_autopm_get_interface_burst);
+
+/**
* usb_autopm_set_interface - set a USB interface's autosuspend state
* @intf: the usb_interface whose state should be set
*
@@ -1467,7 +1499,7 @@ int usb_autopm_set_interface(struct usb_
{
int status;
- status = usb_autopm_do_interface(intf, 0);
+ status = usb_autopm_do_interface(intf, 0, 0);
dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
__FUNCTION__, status, intf->pm_usage_cnt);
return status;
@@ -1524,7 +1556,7 @@ int usb_external_resume_device(struct us
usb_pm_lock(udev);
udev->auto_pm = 0;
- status = usb_resume_both(udev);
+ status = usb_resume_both(udev, 0);
udev->last_busy = jiffies;
usb_pm_unlock(udev);
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -442,6 +442,7 @@ extern struct usb_device *usb_find_devic
#ifdef CONFIG_USB_SUSPEND
extern int usb_autopm_set_interface(struct usb_interface *intf);
extern int usb_autopm_get_interface(struct usb_interface *intf);
+extern int usb_autopm_get_interface_burst(struct usb_interface *intf);
extern void usb_autopm_put_interface(struct usb_interface *intf);
static inline void usb_autopm_enable(struct usb_interface *intf)
Patches currently in gregkh-2.6 which might be from [email protected] are
driver/sysfs-implement-sysfs_find_dirent-and-sysfs_get_dirent.patch
driver/sysfs-use-sysfs_mutex-to-protect-the-sysfs_dirent-tree.patch
driver/pm-remove-pm_parent-from-struct-dev_pm_info.patch
driver/pm-remove-saved_state-from-struct-dev_pm_info.patch
driver/pm-simplify-suspend_device.patch
driver/sysfs-consolidate-sysfs-spinlocks.patch
driver/sysfs-implement-sysfs_flag_removed-flag.patch
driver/sysfs-implement-sysfs_get_dentry.patch
driver/sysfs-make-directory-dentries-and-inodes-reclaimable.patch
driver/sysfs-make-kobj-point-to-sysfs_dirent-instead-of-dentry.patch
driver/sysfs-make-sysfs_drop_dentry-access-inodes-using-ilookup.patch
driver/sysfs-move-sysfs_drop_dentry-to-dir.c-and-make-it-static.patch
driver/sysfs-rename-sysfs_dirent-s_type-to-s_flags-and-make-room-for-flags.patch
driver/sysfs-restructure-add-remove-paths-and-fix-inode-update.patch
driver/pm-remove-prev_state-from-struct-dev_pm_info.patch
driver/pm-do-not-check-parent-state-in-suspend-and-resume-core-code.patch
driver/pm-remove-power_state.event-checks-from-suspend-core-code.patch
usb/usb-add-usb-persist-facility.patch
usb/usb-core-hub.c-prevent-re-enumeration-on-hnp.patch
usb/usb-add-reset_resume-device-quirk.patch
usb/usb-don-t-unsuspend-for-a-new-connection.patch
usb/usb-implement-pm-freeze-and-prethaw.patch
usb/usb-add-usb_autopm_get_interface_burst.patch
usb/usb-disable-file_storage-usb_config_att_wakeup.patch
usb/usb-interface-pm-state.patch
usb/usb-make-hub-driver-s-release-more-robust.patch
usb/usb-move-bus_suspend-and-bus_resume-method-calls.patch
usb/usb-remove-locktree-routine-from-the-hub-driver.patch
usb/usb-remove-references-to-dev.power.power_state.patch
usb/usb-make-device-reset-stop-retrying-after-disconnect.patch
usb/usb-add-power-persist-device-attribute.patch
usb/usb-add-reset_resume-method.patch
usb/usb-remove-__usb_port_suspend.patch
usb/usb-remove-excess-code-from-hub.c.patch
usb/usb-separate-root-and-non-root-suspend-resume.patch
usb/usb-unify-reset_resume-and-normal-resume.patch
usb/usb-add-usb_device_and_interface_info-for-device-matching.patch
usb/usb-ehci-fix-handover-for-designated-full-speed-ports.patch
usb/usb-ehci-ohci-handover-changes.patch
usb/usb-option-fix-usage-of-urb-status-abuse.patch
usb/usb-prevent-char-device-open-deregister-race.patch
usb/usb-rework-c-style-comments.patch
usb/usb-usb-storage-use-kthread_stop-for-the-control-thread.patch
usb/usb-handle-bogus-low-speed-bulk-endpoints.patch
usb/usb-don-t-resume-root-hub-if-the-controller-is-suspended.patch
usb/usb-fix-off-by-1-error-in-the-scatter-gather-library.patch
usb/usb-fix-up-full-speed-binterval-values-in-high-speed-interrupt-descriptor.patch
usb/usb-remove-usages-of-dev-power.power_state.patch
usb/usb-drivers-usb-storage-unusual_devs.h-whitespace-cleanup.patch
usb/usb-storage-implement-autosuspend.patch
-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
lmpx.com only provides a reader for public news (NNTP) servers. It is not
affiliated with the servers or forums shown here and is not responsible for
the content of articles, which is written by their respective authors.